Introduction to the Internet

CSCI 344: Advanced Web Technologies

Fall 2024

This Week’s Readings

• Today’s lecture is based on the readings
• Our first Tutorial will be Friday (during class). We will be examining how platforms gather data about their users to ‘optimize’ their experiences. We will be asking:
• How do these platforms understand who you are?
• How do the categories shape what you see?

Learning Goals for the Week

During this course, we’ll be building different websites and programs that will eventually be part of the Internet. But before we do, we’re going to think a bit about the big picture.

• Today: How the Internet and web work
• Friday: Societal considerations of the Internet:
• How big of an issue is privacy and surveillance on the Internet?
• How do Internet business models shape what gets seen and by whom?

Let’s find out what you already �know about the Internet...

Before we talk about the particulars of the Internet, let’s define it…

What is the Internet?

• Global network of servers…satellite, underground cables, wireless networks, interconnection.
• Internet protocols: IP addresses, TCP
• DNS servers
• Publicly accessible

How are the Internet and the web different?

The term “The Internet” has many meanings

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• “The Internet” can refer to the technical infrastructure (e.g. fiber optic cables, “last mile” networks, data centers, and TCP/IP) – discussed today.
• “The Internet” also refers to the “social life of the Internet”(i.e., content and services the run on top of internet infrastructure) – discussed Friday.

What’s the difference between the Internet and the Web?

Oftentimes “The Web” and “The Internet” are used interchangeably. But from a CS perspective, they’re very different:

• The Internet refers to the physical network infrastructure + TCP/IP protocol
• The Web is one application that runs on top of the internet (others include zoom, email, telnet, networked television, ssh, gaming engines, etc.).

Some questions about the Internet...

1. What is the cloud?
2. Who invented the Internet?
3. Where is the Internet?
4. What is TCP/IP?
5. What is DNS?
6. Who controls the Internet?
7. What is Net Neutrality?
8. Who can access your data over the internet?

What is the cloud? What are some examples of cloud services?

• The cloud is basically having access to someone else’s computer(s)
• Refers to software and information and computing services (including storage) that run on someone else’s computer instead of on yours
• Cloud services can be accessed through a Web browser like Firefox or Google Chrome, through mobile devices, IoT services, etc.
• What this means is that your computer is constantly interacting with the cloud.
• Bottom line: your devices are interacting with other services and systems (and by extension other businesses and people) all of the time. This isn’t necessarily a bad thing, but it’s important to think about.

Who Invented the Internet?

• The internet began as ARPANET, an academic research network that was funded by the military (DARPA), beginning in 1969
• In 1973, Vint Cerf and Bob Kahn began work on TCP/IP, the next networking standards that became the foundation of the modern internet
• In 1981 funding for the internet shifted to the NSF, which funded the long-distance networks that served as the internet’s backbone until 1994
• In 1994, the Clinton Administration privatized the internet backbone

Source: https://www.vox.com/2014/6/16/18076282/the-internet

Source: https://www.vox.com/a/internet-maps

Where is the Internet?

Three primary components:

1. The Internet Backbone�Long-distance networks — mostly on fiber optic cables — that carry data between data centers and consumers
2. The “Last Mile” �The part of the internet that connects homes and small businesses to the internet.
3. Data Centers�Can be located anywhere in the world, but they are often located in remote areas where land and electricity are cheap.

Source: https://www.vox.com/2014/6/16/18076282/the-internet

Internet “Backbone”: Global

Internet “Backbone”: National

• A very high-speed data transmission line that provides networking facilities to relatively small but high-speed Internet service providers all around the world.
• Some of the largest companies running different parts of the Internet backbone include UUNET, AT&T, GTE Corp. and Sprint Nextel Corp.

Source: http://computer.howstuffworks.com/bpl4.htm

The “Last Mile”: Local

• The final connectivity leg between the telecommunication service provider and an individual customer (e.g. Comcast, RCN, etc.).
• The most widely used last mile technologies are DOCSIS (xDSL Cable and Cable Modem Access), fiber optic, or wireless access.

Source: http://computer.howstuffworks.com/bpl4.htm

Pictured: A Google Data Center

Who controls the Internet?

• No one runs the Internet. It’s organized as a decentralized network of networks.
• Thousands of companies, universities, governments, and other entities operate their own networks and exchange traffic with each other based on voluntary interconnection agreements
• There are technical standards committees (ICANN, IETF, etc.) that do meet and agree on rules of traffic exchange
• Governments can filter and block traffic (as can companies, schools, etc.)

Source: https://www.vox.com/2014/6/16/18076282/the-internet

What is TCP/IP?

TCP (Transmission Control Protocol): Ensures reliable transmission of data across a network.

• Breaks down data into smaller packets before they are sent.
• Ensures packets are delivered, checks for errors, and reassembles them in the correct order on the receiving end.
• On the other hand, UDP (User Datagram Protocol) does not ensure that packets are delivered (which makes it faster…and this is sometimes OK).
• Provides flow control and congestion control to maintain the stability of the network.

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Source: ChatGPT: https://chatgpt.com/share/184fead0-75f7-420e-b57b-82a32f53d532

What is TCP/IP?

IP (Internet Protocol): Handles addressing and routing of packets to ensure they reach the correct destination.

• Assigns a unique IP address to each device on the network.
• Determines the best route for data to travel across the network.
• Data doesn’t necessarily arrive in order (up to TCP/UDP to figure that out).

Source: ChatGPT: https://chatgpt.com/share/184fead0-75f7-420e-b57b-82a32f53d532

Why would you use UDP v. TCP?

UDP:

• Used for time-sensitive applications (e.g. gaming, zoom, playing videos, or Domain Name System (DNS) lookups)
• If a packet drops here or there, oh well!

TCP:

• Used when you need data integrity (# of bits sent === # of bits received).
• Documents, etc.
• Slower

Source: ChatGPT: https://chatgpt.com/share/184fead0-75f7-420e-b57b-82a32f53d532

What is DNS?

DNS (Domain Name System) is a way of assigning human-readable addresses to IP addresses (so people don’t have to remember long sequences of numbers).

• When a client (e.g. browser) asks for a website at a domain name, the browser first looks in its cache for the associated IP, then to a DNS resolver (usually your ISP).
• If that particular resolver can’t find it, a series of queries are issued to other DNS servers ‘til one of them finally has the IP address.
• That domain name / IP address mapping are then propagated to the querying DNS servers and cached (so it’s faster next time).

Source: ChatGPT: https://chatgpt.com/share/184fead0-75f7-420e-b57b-82a32f53d532

DNS Sample Lookup Table

What happens in a DNS Attack?

What is Net Neutrality?

The principle that Internet service providers and governments should treat all data on the Internet the same, not discriminating or charging differentially by user, content, site, platform, application, type of attached equipment, or mode of communication. In the US, this is controlled by the FCC.

1. Repealed in 2015, championed by Ajit Pai
2. Biden administration revisiting this determination (more here)
3. Recent Supreme Court ruling halts reinstatement
• https://publicknowledge.org/supreme-court-decision-in-loper-jeopardizes-net-neutrality-all-consumer-protections/
• Decoder Podcast (The Verge)

Arguments for NN

Arguments against NN

How do wireless communications work?

Radio waves: Each form of wireless communication uses a different spectral frequencies:

• Some are licensed (e.g., Verizon, AT&T, etc. each “rent” different parts of the spectrum)
• Some are open for anyone to use (e.g., for WiFi, Bluetooth, etc.)

Who can access your data (transmission & storage)?

What did the 2013 Snowden leaks reveal?

• Britain's “Tempora” taps fiber optic cables around the world
• NSA could hack into Google and Yahoo data centers w/o their knowledge
• Verizon had been providing the NSA w/all of its phone records
• NSA can request user data from companies, which they are compelled to deliver on by law (PRISM)
• NSA undermines encryption via backdoors and promoting the use of weaker algorithms

Sources:

• https://mashable.com/2014/06/05/edward-snowden-revelations/#u2nj85eX6PqT
• https://www.theguardian.com/world/interactive/2013/nov/01/snowden-nsa-files-surveillance-revelations-decoded#section/1 (Worth a read!)

Part 2: �Intro to the Web